Supplementary Figure 6: Evaluation of the specificity of SNA lectin surface staining for determination of cellular St6gal1 activity.

(a) B and T cells of wild-type (WT) and St6gal1^−/− mice were stained with a FITC-coupled SNA-lectin to determine the levels of surface sialic acid. (b) Immunofluorescence microscopy of spleens of WT and St6gal1^−/− mice determining the levels of sialic acid on B220⁺ B cells by co-staining with an antibody against B220 (A488, green) and a SNA lectin (QDot705, red). (c) Human CD19⁺ B cells were stained with FITC-stained SNA-lectin to determine the levels of surface sialic acid. B cells were pre-treated with neuraminidase (100 mU, 1h at 37°C) or iodate (2mM, 1h at 4°C) to remove sialic acid where indicated. Error bars represent SEM*P < 0.05, **P < 0.01, ***P < 0.001; Student’s t test.